Part of the stadium that will host the World Cup opener in Brazil next year collapsed on Wednesday, causing significant damage and killing three people, authorities said.

The accident could delay the delivery of the stadium in Sao Paulo by FIFA's December deadline to have all 12 venues ready. The Itaquerao Stadium was practically completed before the collapse.

Television images showed that a huge metal structure buckled atop the stadium, destroying part of the stands in the east side of the venue. A LED panel installed outside the venue also was hit.

Firefighter official Mauro Lopes said in a radio interview that at least three people died in the accident, which apparently happened when a crane collapsed on top of the metal structure.